In the known high-speed wireless transmission systems, the signals transmitted by the transmitter reach the receiver by following a plurality of paths resulting from the many reflections of the signal on the walls, furniture or similar elements. When combined at the level of the receiver, the phase differences between the different rays having taken paths of different lengths gives rise to an interference figure that can cause fading or a significant degradation in the signal.
Now, the location of the fading changes over time according to the modifications in the environment such as the presence of new objects or the movement of people. The fading due to multipaths can lead to significant degradations both at the level of the quality of the signal received and at the level of the system performances. To overcome these fading phenomena, the technique most often used is a technique that implements spatial diversity.
This technique consists, among other things, of using a pair of antennas with wide spatial coverage connected by feed-lines to a switch. However, the use of this type of diversity requires a minimum spacing between the radiating elements to ensure that there is sufficient decorrelation of the channel response viewed from each radiating element. An inherent disadvantage to its implementation is the distance between the radiating elements that present a cost, particularly in terms of size and substrate.
Other solutions have been proposed to overcome this problem. Some of these solutions use diversity of radiation as described for example in the French patent A-2 828 584 in the name of the applicant.